How or why does the wax of a candle catch on fire?

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   Candle Reviewsposted 9 years ago

   How or why does the wax of a candle catch on fire?
   
   I had a very scary experience a few days ago.  The two wick candle I was burning literally caught fire.  All the wax int he candle was on fire, and huge leaping flames were coming out of the top.  My house could have burned down.  I was pretty upset.  We had to put it out with a fire extinguisher, and I just got done spending over an hour cleaning up the charred shards of glass and wax everywhere in my bathroom.  It was awful, and almost makes me nervous to trust candles.  I did nothing wrong, and in fact trimmed the wicks down to almost nothing before lighting.  Very scary and unsettling.

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   Joshtheplumberposted 9 years ago

   I thought this would be a question about the physics involved, but it sounds more like you had a defective candle. Strictly speaking, solids and liquids do not burn- only gases. The heat of the flame liquifies the wax and it is drawn up into the wick through capillary action before evaporating and burning from a gaseous state. For what you described to have happened, the surface of the wax must have somehow gotten hot enough to combust. Since you trimmed the wicks, my best guess is that there was something other than wax in the mixture that was too flammable or in too high of a concentration.
   
   Best to report this to the manufacturer.

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      Candle Reviewsposted 9 years agoin reply to this

      I think you might be right Joshua.  It was pretty scary and its of concern because others might not burn candles as safely as I try to do.  Some burn them and fall asleep or near curtains or on a bookshelf, etc.  Thanks so much the info and answer.

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   eugbugposted 9 years ago

   I thought this was a physics question also. As Joshua notes, solids and liquids don't burn. They have to become volatile first and become gas or vapor, which mixes with oxygen in the air for combustion to occur. When you light the wick of a candle, solid wax impregnated in the wick from the last time it was lighting melts, vaporises and burns. The heat of combustion melts wax from underneath the burn point and capillary action results in a steady stream of molten wax soaking upwards.
   Its possible the two wicks were oversized and the candle went into a "runaway" state with enough heat to melt the wax at the top. Alternatively if the candle was a scented type, possibly volatile compounds containing the scent e.g. alcohol was added and this didn't mix properly but collected in a pocket at the top of the candle.

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      Candle Reviewsposted 9 years agoin reply to this

      Thanks so much Eugene, as it helps me to understand more what could have happened.  Between yours and Joshua's answer, this helps paint a good picture of the why it might have happened.  The science behind it is good to know.  Thanks again.

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